Browsing by Author "Roşu, Tudor"

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SOME NEW Cu(II), Co(II) AND Ni(II) COMPLEXES CONTAINING AN ONS DONOR THIOSEMICARBAZONE: SYNTHESIS, CRYSTAL STRUCTURES AND BIOLOGICAL ACTIVITY.
(Academia de Ştiinţe a Moldovei, 2015) Pahontu, Elena Mihaela; Julea, Felicia; Chumakov, Yurii; Petrenko, Peter A.; Roşu, Tudor; Gulea, Aurelian
SYNTHESIS OF SOME NEW COMPLEXES OF Cu(II) WITH BIOLOGICAL ACTIVITY
(Academia de Ştiinţe a Moldovei, 2006) Roşu, Tudor; Gulea, Aurelian; Negoiu, Maria; Pasculescu, Simona
The paper presents the synthesis of complex combinations of Cu(II) with Schiff bases obtained through the condensation of 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (AAP) with ohidroxybenzaldehyde (SAL), terephthalic aldehyde (TA), 2-hidroxy-3-metoxy-izofthalaldehyde (FV), 2,3-dihidroxy-izofthalaldehyde (DHV) respectively. The characterization of the newly formed complexes was done by 1H RMN, UV-VIS, IR and RES spectroscopy, thermal derivatographic analysis and molar electric conductibility. The RES spectrum for the complex combination [Cu(C18H16N3O2)(H2O)]Cl, as a powder, at room temperature, indicates values of tensor{g} confirming the symmetry C2v of the Cu2+ pentacoordinated ion. For the low symmetry Cu(II) ions, the fundamental state for the paramagnetic electron is not described by a single d function, but there is a mixture of them. The mixtures degree of these functions increases as the symmetry decreases. The high values of the {g} tensor confirm low symmetry. The RES spectra for the complex combination [Cu2(C30H28N6O2)(SO4)2] as a powder, at room temperature, with values of the {g} tensor, g1 = 2,088 and g2 = 2,446, confirms the Td symmetry. As it is noticed, the spectrum does not present interactions that might indicate a hyperfine structure. The lack of the hyperfine structure or the presence of very small hyperfine splitting for the Cu2+ ion in Td symmetry, or lower symmetry were explained by C.A. Bates et all, by mixing the 4pz orbital of the metallic ion with the 3dxy orbital defining the fundamental state. The determination of the anti-microbial activity of the ligands and of the complex combinations was realized on stems of Escherichia coli, Klebsiella pneumoniae, Acinetobacter boumanii, Pseudomonas aeruginosa, Staphylococcus aureus and Candida sp. The results of the qualitative and quantitative testing of the anti-microbial activity proved that all prepared combinations are very active especially when in contact with the stems of Ps. aeruginosa, A. Boumanii, E. coli and S. aureus.
Synthesis, Caracterization, Antimicrobial and antiproliferative Activity Evaluation of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) Complexes with Isoniazid - Derived Compound
(Molecular Diversity Preservation International (MDPI), 2017) Pahonţu, Elena; Ilieş, Diana-Carolina; Shova, Sergiu; Oprean, Camelia; Păunescu, Vergil; Olaru, Octavian Tudorel; Rădulescu, Flavian Ştefan; Gulea, Aurelian; Roşu, Tudor; Drăgănescu, Doina
Hydrazone complexes of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) with N-isonicotinoyl-N′-(3-metoxy-2 hydroxybenzaldehyde)-hydrazone (HL) were synthesized and characterized by different physico-chemical techniques including elemental and thermal analysis, magnetic susceptibility measurements, molar electric conductivity, as well as IR (infrared), 1H-NMR and 13C-NMR (hydrogen and carbon nuclear magnetic resonance, UV-Vis (ultraviolet-visible), FAB (fast atom bombardment), EPR (electron paramagnetic resonance), and mass spectroscopies. The crystal structure of ligand was determined by single crystal X-ray diffraction studies. Spectral data showed that hydrazone behaves as an ONO tridentate ligand through the azomethine nitrogen, phenolate and keto oxygen atoms. For the copper(II) complexes, metal–ligand bonding parameters were evaluated from the EPR spectra. These parameters indicate the presence of in-plane π bonding. In addition, the f values of complexes 1–4 indicate small distortion from planarity. The effect of these complexes on proliferation of human breast cancer (MCF-7 and SKBR-3), human melanoma (A375), lung adenocarcinoma cells (NCI-H1573) and their antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Candida albicans strains were studied and compared with those of free ligand. The ligand and complexes 1–3 showed significant antimicrobial activity against the Gram-positive bacteria Staphylococcus aureus and Candida albicans in comparison to the control drugs. The complexes 2–4 could be potential antitumor agents, leading to a significant improvement of the cytotoxic activity when compared with HL.
SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY OF NOVEL CU(II), PD(II), PT(II) COMPLEXES WITH 2-HYDROXY-8-ETHYLTRICYCLO[7.3.1.0.2,7]TRIDECANE-13-ONE THIOSEMICARBAZONE
(Academia de Ştiinţe a Moldovei, 2015) Pahontu, Elena Mihaela; Paraschivescu, Codruta; Ilies, D.; Poirier, Donald; Oprean, Camelia; Gulea, Aurelian; Roşu, Tudor
SYNTHESIS, CHARACTERIZATION, CRYSTAL STRUCTURES OF NICKEL(II), PALLADIUM(II) AND COPPER(II) COMPLEXES WITH 2-FURALDEHYDE-4- PHENYLTHIOSEMICARBAZONE
(Academia de Ştiinţe a Moldovei, 2012) Ilies, D.; Pahontu, Elena Mihaela; Mezey, Reka-Stefana; Shova, Sergiu; Gulea, Aurelian; Roşu, Tudor
SYNTHESIS, STRUCTURAL AND SPECTRAL STUDIES OF Cu(II) AND V(IV) COMPLEXES OF A NOVEL SCHIFF BASE DERIVED FROM PYRIDOXAL. ANTIMICROBIAL ACTIVITY
(Academia de Ştiinţe a Moldovei, 2012) Mezey, Reka-Stefana; Pahontu, Elena Mihaela; Ilies, D.; Shova, Sergiu; Gulea, Aurelian; Roşu, Tudor